Polyimide resins having excellent film properties such as heat resistance, mechanical properties and electric properties have been conventionally used for an interlayer insulating film or surface protection film of a semiconductor device. However, when a non-photosensitive polyimide resin is used as an interlayer insulating film or the like, a patterning process uses a positive resist, which requires etching and resist removal processes or the like, resulting in a more complex manufacturing process. The use of a photosensitive polyimide resin exhibiting excellent photo-sensitivity has investigated accordingly. Examples of such a photosensitive polyimide resin composition include positive photosensitive resin compositions consisting of a polyimidic acid, an aromatic bisazide compound and an amine compound described in Japanese Patent Publication No. 3-36861 (Patent Document 1). However, a development step in a patterning process of a photosensitive polyimide resin requires an organic solvent such as N-methyl-2-pyrrolidone and ethanol, which is problematic in terms of safety and environmental impact.
Thus, a positive photosensitive resin composition has recently been developed as a patterning material which can be developed with an aqueous alkaline solution such as an aqueous tetramethylammonium hydroxide (TMAH) solution used in a fine patterning process for a semiconductor. For example, Japanese Patent Publication No. 1-46862 (Patent Document 2) has described a non-chemical amplified positive photosensitive resin composition consisting of a polybenzoxazole precursor and a diazoquinone compound as a photosensitizing agent. M. Ueda et al., Journal of Photopolymer Science and Technology, Vol. 16(2), pp. 237 to 242 (2003) (Non-Patent Document 1) reported a non-chemical amplified positive photosensitive resin composition consisting of a polybenzoxazole precursor and a 1,2-naphthoquinonediazide-5-sulfonate. In addition, K. Ebara et al., Journal of Photopolymer Science and Technology, Vol. 16(2), pp. 287 to 292 (2003) (Non-Patent Document 2) reported a chemically amplified positive photosensitive resin composition consisting of a polybenzoxazole precursor protected by an acid-decomposable group and a photoacid generator.
In such a photosensitive resin composition, its structure is changed by heating to form a benzoxazole ring, resulting in excellent heat resistance and electric properties. For example, a polybenzoxazole precursor described in M. Ueda et al., Journal of Photopolymer Science and Technology, Vol. 16(2), pp. 237 to 242 (2003) (Non-Patent Document 1) forms a benzoxazole ring by heating after development with an alkaline solution as shown in the following reaction schemes A1 and A2. Since the benzoxazole ring is a stable structure, an interlayer insulating film or surface protection film prepared using a photosensitive composition consisting of the polybenzoxazole precursor exhibits excellent film properties such as heat resistance, mechanical properties and electric properties.


In the field of manufacturing a semiconductor device recently, a higher density, higher integration and a finer wiring pattern in the device have been further needed. Consequently, requirements have been stricter to a photosensitive resin composition used for an interlayer insulating film, surface protection film or the like. However, in view of resolution, any positive photosensitive resin composition described in the above Documents is not satisfactory.
It is therefore needed to develop photosensitive resin compositions which can be developed with an alkaline solution and exhibit higher resolution while maintaining the conventional film properties.    Patent Document 1: Japanese Patent Publication 3-36861    Patent Document 2: Japanese Patent Publication 146862    Non-Patent Document 1: M. Ueda et al., Journal of Photopolymer Science and Technology, Vol. 16(2), pp. 237 to 242 (2003)    Non-Patent Document 2: K. Ebara et al., Journal of Photopolymer Science and Technology, Vol. 16(2), pp. 287 to 292 (2003)